Something Eating Roots

My cucumber plant has been eaten away at the root I discovered. What it was I can't identify but it's a larvae of some kind with a shiny brown/yellow hard shell-type finish to it. It crunched when I stood on the 3 of them. It would be great if you could help in how to get rid of them. They are contained in a whisky barrel I have in my greenhouse.

If you send me a picture of them, I might be able to identify them. I can say that if you treat the plants and soil with neem oil, this will help to get rid of them. Neem oil basically shuts down the systems of any pest that eats plants that have been treated with neem. Here is more information on neem oil: https://www.gardeningknowhow.com/problems/pests/neem-oil-uses.htm